CAMPUS chiefs were accused today of having "blood on their hands" after America's largest mass shooting.

As police begin to unravel how 32 people were killed in the massacre before the gunman shot himself at Virginia Tech University, the authorities were facing tough questions over why they waited more than two hours to inform staff and students of the first murders.

Many found themselves trapped and terrified when the gunman, instead of fleeing as the authorities suspected, launched a new and more ferocious killing spree at the campus in Blacksburg.

Birmingham student George Barnwell, from Kings Heath, who is in the US on a one-year exchange from Sheffield University, was caught in the chaos.

He said: "Several friends of mine were near to the second incident and took pictures using a mobile phone.

"It is amazing to think that an event like this could have happened in such a quiet town. We are all in shock at the moment."

Survivors described how the calm young Asian man, dressed in what one said was a Boy Scout type uniform, roamed around in search of victims.

"We put a table against the door and when the gunman tried to shoulder his way in and when he saw that he couldn't, he put two shots through the door."

Some students began to give accounts of the killing spree on internet sites as it unfolded.

The tragedy began at 7.15am (12.15pm British time) yesterday in West Ambler Johnston Hall, a student dormitory, when two victims, a man and a woman, were gunned down.

Around two hours later 30 people, including a number of staff, were killed when the gunman began firing in Norris Hall, an engineering building containing classrooms and laboratories.

The un-named killer then took his own life.

There was speculation he may have been a disgruntled boyfriend seeking revenge after discovering his girlfriend was having an affair.

But although police were called to the first shooting at 7.15am, the authorities did not notify the rest of the student population until 9.26am, when an email was sent giving brief details and asking them to report any suspicious activity.

Students said that there were no public-address announcements on campus after the first shots.

"I think the university has blood on their hands because of their lack of action after the first incident," said Billy Bason, 18.

Charles Steger, president of the university based in Blacksburg, said they had "locked down" where they believed the first shooting had occurred.

He said: "We had no reason to suspect any other incident was going to occur."

Mr Steger added: "We concluded the incident in Ambler Johnston was domestic in nature, in fact we had some reason to think the shooter had left the campus, in fact may have been leaving the state."

Overnight, a vigil was held at the university as students, staff and those living close to the campus attempted to come to terms with what had happened.

Virginia governor Timothy Kaine said it was "too early" to draw conclusions over how campus authorities handled the aftermath of the massacre.

Speaking as he cut short a trip to Tokyo to return to the US, he said: "It is a very tragic day for us in Virginia. My reaction was just shock. My first thought was just how tragic this was for the university."

Virginia Tech police chief Wendell Flinchum told reporters officers were still in the process of identifying victims and informing the families.

Fifteen other victims are being treated at local hospitals.

Mr Flinchum said officers had recovered two weapons, and ballistic tests were being carried out to establish a link between the two shootings.

Although it is believed a lone gunman was responsible for the killings, Mr Flinchum said investigators were "exploring all possibilities".

Mr Flinchum said police had identified and interviewed a "person of interest" in connection with the shooting, but gave no further details.

Police are believed to have a preliminary identity for the gunman, but have not yet released it.

The horror of the tragedy began to emerge last night with reports the killer was armed with two 9mm handguns and may have lined up and shot a classroom of students one by one.

A number of students were injured jumping from buildings as they fled the gunman while in another incident the killer was said to have fired through a door barricaded by students.

Trey Perkins, who was in a German class in Norris Hall, said the gunman burst into the room at about 9.50am. He opened fire for around a minute and a half.

He said the gunman shot the professor in the head before firing at students.

Mr Perkins said the gunman was about 19 and had a "very serious but very calm look on his face".

Miss Sheehan, who was in the same class, told the student newspaper, the Collegiate Times, the gunman had "peeked in twice" like he was looking for somebody, before he started shooting.

She described the gunman as "just a normal-looking kid, Asian, but he had on a Boy Scout-type outfit. He wore a tan button-up vest, and this black vest, maybe it was for ammo or something".

She added, "My professor, Herr Bishop, I'm not sure if he's alive."

Mr Steger said police were forced to break through doors at Norris Hall that had been chained shut from the inside.

He said: "They heard gunshots. They followed the sounds of gunshots to the second floor when the gunshots stopped.

"They discovered the gunman who had taken his own life, there was never any engagement with the gunman by police."

US president George Bush offered his condolences to those affected by the tragedy, which will put the debate about relaxed US gun control laws firmly back on the political agenda.

He said: "School should be places of safety and sanctuary and learning. When that sanctuary is violated the impact is felt in every American class and in every American community.

"Today our nation grieves with those who have lost loved ones at Virginia Tech."

The Queen, who will travel to Virginia next month during a US state visit, also offered her sympathies.

A Buckingham Palace spokeswoman said: "The Queen was shocked and saddened to hear of the news of the shooting in Virginia."